Display elements such as static digital images or frames of motion video may include a richness of observable content. An observer, for example, may gaze or fixate on various portions or areas of interest when viewing a display element. The observer's gaze or fixation on the areas of interest may provide useful information that may characterize the observer's interests. Also, when combined with information obtained from viewing a multitude of display elements having similar areas of interest, a more detailed characterization of the observer's interests may be provided.